An Eruptive Circular-ribbon Flare with Extended Remote Brightenings
An Eruptive Circular-ribbon Flare with Extended Remote Brightenings
复制标题
DOI：
10.3847/1538-4357/ab9cbe
复制
发表时间：
2020-07
期刊：
影响因子：
--
通讯作者：
Chang Liu;A. Prasad;Jeongwoo Lee;Haimin Wang
中科院分区：
文献类型：
--
作者：
Chang Liu;A. Prasad;Jeongwoo Lee;Haimin Wang
我们研究了2013年11月10日爆发的X1.1圆带状耀斑，结合多波长观测和使用非无力场方法的日冕场重建。在第一阶段，通过磁重联的两个轻度扭曲的剪切弧，这是嵌入下的扇形圆顶与零点（NP）之间的长丝形式。这种重连似乎是由光球剪切和会聚流驱动的，与耀斑相关的横向场变化一致。由于环面的不稳定性，暗条的南部部分向上升起，并推压NP。当加速电子沿着扇形沉淀并沿着具有高挤压因子（Q）值的准分离面向外传播时，诱导的NP重联在西边产生了环形带和初始的远程增亮，在这里，准分离面具有幕状形状。在第二阶段，通量绳的南端脱离表面，依次破坏圆顶和覆盖场，并以鞭打的方式爆发，成为部分晕日冕物质抛射。这导致了增强的耀斑发射和快速移动的远程增亮在磁幕的脚点，这跨越了一个非常广泛的区域，也与日冕昏暗。这是一个罕见的爆发性环带耀斑的例子，其中完全观察到了磁通绳从形成到成功喷发出圆顶的演变以及由此产生的异常扩展的远程增亮。
We study an eruptive X1.1 circular-ribbon flare on 2013 November 10, combining multiwavelength observations with a coronal field reconstruction using a non-force-free field method. In the first stage, a filament forms via magnetic reconnection between two mildly twisted sheared arcades, which are embedded under the fan dome associated with a null point (NP). This reconnection seems to be driven by photospheric shearing and converging flows around the inner two arcade footpoints, consistent with the flare-related changes of the transverse field. The southern portion of the filament rises upward due to torus instability and pushes against the NP. The induced NP reconnection then generates the circular ribbon and the initial remote brightening in the west, as accelerated electrons precipitate along the fan and propagate outward along quasi-separatix surfaces with high values of the squashing factor (Q) in the envelope fields, which have a curtain-like shape here. In the second stage, the southern end of the flux rope breaks away from the surface, sequentially disrupts the dome and overlying fields, and erupts in a whipping-like fashion to become a partial halo coronal mass ejection. This leads to an enhanced flare emission and fast-moving remote brightenings at the footpoints of the magnetic curtain, which span a remarkably broad region and are also associated with coronal dimmings. This is a rare example of eruptive circular-ribbon flares, in which the evolution of a flux rope from its formation to successful eruption out of the dome and the resulting unusually extended remote brightenings are completely observed.